On StackExchange the equivalent of #help would seem to be StackOverflow while #codereview would be analogous to the CodeReview site. The essential difference on SE is that SO is for getting help with code that is not working while CR is for comments on style and optimization of code that does work in its current state.

Another key difference is that #help topics should focus on the “minimal, complete, and verifiable example” paradigm while #codereview topics should focus on “complete unedited codebase”.

I like the idea of a code review forum here primarily because this community has proven welcoming, friendly, and helpful.